Burners for liquid fuel



Oct. 18, 1960 J. v. GUDMAND-HOYER 2,956,621

BURNERS FOR LIQUID FUEL Filed 001;. 24,. 1957 I6 [5E9 I Juuus v. GUDMM/b-WYER IVVEVTOR A'FFMMEY United States Patent BURNERS FOR LIQUID FUEL Julius Villiam Gudmand-Hoyer, Dalumvej 9, Frueus Boge, near Odense, Denmark Filed Oct. 24, 1957, Ser. No. 692,190

Claims priority, application Denmark Oct. 30, 1956 1 Claim. (Cl. 158-91) The invention relates to burners for liquid fuel. The invention may be used both in connection with the socalled evaporation burners in which the oil is evaporated in an evaporator whereupon the vapours formed are ignited, and in connection with the so-called atomization burners in which the liquid fuel prior to ignition is atomized or reduced to the form of a mist in the combustion air. Known burners of this kind will in many cases suifer from the disadvantage that the flame from the mouth of the burner will concentrate along the axis of the burner and therefore will not efiectively heat such parts of the wall of the furnace, in which the burner is situated, which are placed abreast of and behind the burner.

It is an object of the present invention to provide a burner the flame of which is dispersed laterally. A further object of the invention consists therein at the same time to make it possible by a supply of heated combustion air to the flame to ensure a complete and therefore sootless combustion. Hereby the eifect is attained that a very hot flame free from soot is made in the furnace capable of contacting walls placed abreast of and behind the burner.

These objects are attained according to the invention by the use of a screen placed in front of a unit for sub dividing the fuel and having a flame mouth, the screen being so constructed that it will spread the flame coming from the mouth laterally, and further being provided with hollow spaces for the passage of combustion air to the flame. By means of a burner constructed in this manner a strong heating will take place also of the heated surfaces situated abreast of and behind the burner, with the result that all the heating surfaces of the furnace will be effectively utilized.

According to the invention the screen may, outside the flame mouth, be provided with a circular, rearward protruding edge at a distance from the flame mouth. The gaseous combustion products will thereby be forced to flow to the rearward from the edge of the screen, for instance at an outward and downward angle. This will be of particular importance in boilers for central heating, as in this way the lowermost heating surfaces of the furnace will be especially effectively utilized.

The burner may according to the invention be provided with an air supply pipe debouching centrally or almost centrally in the screen. Thereby particularly favourable conditions of flow will be achieved inasmuch as the air leaving the pipe will cause a radial, outward flow. According to the invention the air supply pipe may extend through the screen and form a passage therein. As the screen will be heated by the combustion, the air entering the passage will be heated and this will contribute to attaining an eflicient combustion. The passage may according to the invention extend from the centre of the screen to its edge and thence back to the central opening. This will cause a strong heating of the air while at the same time the screen will be cooled so that it may withstand the heat.

2,955,621 Patented Oct. 18, 1960 ice The drawing shows some embodiments of burners according to the invention, 7

Fig. 1 showing an axial section through an evaporator burner,

Fig. 2 an axial section through an atomizer burner, and

Fig. 3 an axial section through another embodiment of an atomizer burner.

In Fig. 1 the present invention is applied in combination with an evaporator unit for subdividing the fuel by evaporation. The evaporation and ignition here take place in a manner known per se, in using a plate container with wall 1 and bottom 2 is used. Wall 1 is provided with a large number of small openings 3. The centre of the bottom 2 has an upward pipe 4. The container 1, 2 is enclosed in a plate jacket with sidewall 5 and bottom 6. The upper part of wall 5 is curved inwards past the upper edge of side wall 1 to which it is connected by an airtight joint. The side of the jacket 5, 6 is connected with an air supply pipe 7. This pipe con-, tains also an oil supply pipe 8 which is connected with the bottom 2 of the container 1, 2.

The upward projecting pipe 4 holds a pipe 9 which extends farther upwards and carries a screen 10 extending over the container 1, 2 and having an outer, circular and downwardly bent edge or end portion 11. The screen defines therewithin a system of passages of which the outer or upper passage 12 communicates with the opening in the upper end of pipe 9 while the inner or lower passage 13 communicates with a central downward opening 14 surrounding pipe 9 and situated a little above the upper edge of the container 1, 2. In that part of outer passage 12 which is directly above the opening at the upper end of pipe 9 an adjustable throttle 15 is mounted on a screw spindle 16 passing through a threaded hole in the top of the screen 10 and provided at its top with a handle 17.

When the furnace is to be used oil and are taken to the burner through pipes 7 and 8. The oil at the bottom of the burner is ignited in the usual manner. Primary air for the combustion of the oil will stream through holes 3 and a flame will form outside each hole. In addition air will flow through pipes 4 and 9, on through passages 12 and 13 and out through the mouth 14. This air serves as secondary air. The combustion products will flow from the container 1, 2 up through the flame mouth in the top of the container where they will be mixed with the secondary air from the opening 14. By the screen 10, 11 the flame will be forced to flow out- Wards and downwards so that the lower part of the furnace which is not shown on the drawing, but in which the burner is placed, will be strongly heated. This will be a special advantage when the burner is located in the furnace of a central heating boiler which in the lower part of the furnace will have heating surfaces which would not otherwise be exposed to much heat. The secondary air will be heated by passing up through pipes 4 and 9 and through the passages in screen 10, 11. The flow of secondary air may be controlled by adjustment of the throttle 15.

In the embodiment shown in Fig. 2 the screen is used in combination with a pressure atomizing unit 21 with upward directed flame mouth 22 and atomizing nozzle 23. The screen proper is constructed in the same way as described in the foregoing except that the air supply pipe 9 is situated at the top. Right in front of the flame opening an axial boss 24 with guide surfaces is placed, serving to gently guide the flames.

In the embodiment shown in Fig. 3 the screen is incorresponding manner used in combination with a pressure atomizing pipe unit having a downward directed flame mouth.

The embodiments shown and described are to be con sidered solely by way of examples, as many variations may be made within the scope of the invention, and it is especially pointed out that the burner axis may be arranged -horizontally or at any oblique angle.

I claim:

.A burner for liquid fuel comprising, in combination: a unit for vaporizing the fuel, said unit having a flame mouth through which the flames emanatewhen a vaporized fuel is combusted in said unit; a pipe for secondary combustion air co-axially mounted in .said unit and .having a portion extending outwardly through said flame mouth; and a hollow screen connected with said ,pipe portion, surrounding said flame mouth, and having .a free edge portion .curved toward said unit, the interior of .said

screen communicating with said pipe for receiving secondary air from the latter and the screen having a central outlet opening for secondary .air facing said flame mouth.

References Cited in the file of this patent UNITED STATES PATENTS 1,558,519 Uhl et all. Oct. 27, 1925 1,583,025 'Sturg'is May 4, 1926 1,725,510 Fiske Aug. 20, 1929 1,881,687 et-al. Oct. 11, 1932 1,885,674 Brade Nov. 1, 1932 2,660,230 Denker et a1. Nov. '24, 1953 

